JPH04501823A - Protonated Mannich polymer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Protonated Mannich polymer Menzu stand 1 This invention relates to cationic flocculants used to remove suspended solids from liquids. Ru. More specifically, the invention provides: i) an acrylamide-containing polymer and a secondary amine; Acrylamide polymer backbone by reacting with formaldehyde (Mannich reaction) and ii) forming a plurality of active tertiary aminoalkyl groups along by rapidly acidifying the material, preferably with a combination of organic/inorganic acids. Discloses an acidified flocculant prepared by

Aminomethylated polyacrylamide polymer is used as a flocculant for wastewater treatment, etc. Commercially available products of this type are generally Referred to as hyperpolymers, they are available in a variety of molecular weights and charge densities.

The relative dimensions of the polymer molecules in a cohesive material depend on the nature of the polymer molecules, but is also typically expressed in terms of its intrinsic viscosity rather than its molecular weight, so for example, 1 A Mannich polymer with an intrinsic viscosity of 0 has a molecular weight of approximately 6,000,000. A Mannich polymer with an intrinsic viscosity of 5 has a molecular weight of approximately 2,000,000. has.

Polyacrylamide itself is essentially nonionic. Mannich reaction The tertiary aminoalkyl group formed as a result of the conversion of the acrylamide group is The amount of charge on the Mannich polymer, which provides the cationic nature of the aggregation agent, also related to the number of acrylamide groups converted to tertiary aminomethyl groups by the Hich reaction . The extent of this conversion is referred to as the "charge density" of the resulting polymer, e.g. , a polyacrylamide material with an average of 100 acrylamide groups in each molecule is reacted with amine and formaldehyde in chemical quantities of 25%, the obtained The resulting polymer has an electric potential related to the amount of tertiary aminoalkyl (aminomethyl) groups obtained. If a similar reaction would have a loading density, i.e. about 25%, the same molecule (intrinsic viscosity) of polyacrylamide along the polymer backbone. Performed using equal amounts of secondary amine and formaldehyde to 50% of the acrylamide groups. the resulting polymer has twice the charge as the initial (25%) polymer. One, adjusting the charge density of the Mannich polymer allows the flocculant to be The Mannich type is tailored to balance the charge content (required amount) of the water system. The flocculant is generally about 1-20% flocculant, typically about 2-10% solids. Sold as an aqueous concentrate containing solids. Before using it as a flocculant, the concentrated solution The liquid is further diluted with water to less than 1%, generally less than about 0.5%.

Mannich polymer concentrates have a pH ranging from 10 to 11.5. It takes a man Previous attempts to acidify nihi concentrates resulted in decreased shelf life and The useful properties of coagulant concentrates have been limited to just a few hours.

One problem with the use of Mannich flocculants is that the Mannich reaction is reversible. This means that Therefore, Mannich polymers are degraded and become unpleasantly formalized. Dehyde (current 0SHA standard is less than lppm (8 hours weight) (requires a standard of residual formaldehyde of 100% on the molecule) Even when the acrylamide group is aminomethylated, the charge density of the Mannich flocculant The degree of (PEI), therefore high charge density and relatively low intrinsic viscosity are required. In some applications (e.g. wastewater in paper manufacturing), Mannich polymers can It has no loading density.

Requirements for flocculants used in municipal wastewater treatment will change significantly. Ru. These variable requirements include the following parameters of the wastewater: pH, alkalinity, volatiles. and aerobically digested o+a 0 normal Mannich and Other cationic flocculants are often used with moderate pH 1 low volatility and low levels of preference. Although it works well in wastewater systems with gaseous decomposition sludge, these The aggregation agent has a relatively high pH or a relatively high proportion of volatiles, or is aerobic. This is unsatisfactory in wastewater systems containing high levels of decomposed sludge.

British Patent Specification No. 1°572,386 issued on July 30, 1980 A Mannich-type flocculant having a pH is disclosed. However, this patent document , the acid is diluted to less than 1% solids, most preferably less than 0.25% solids. teaching that it should be added only after the Therefore, the UK patent The acid addition step shown is a UK patent for a 0wI sexualization step carried out immediately before use. The material used in is a mineral acid, preferably sulfuric acid.

1 hole standing Iyu The present invention exhibits improved performance and is much more effective than standard basic Mannich flocculants. Discloses acidified (protonated) Mannich polymers with high stability Ru.

The products of the invention are suitable for use in wastewater systems and paper wastewater applications where higher charge requirements exist. These new compositions have lower residual formaldehyde ( less than lppm), offering higher product safety than standard, basic Mannich products. It has quality and shelf life. In other words, the protonated flocculant is more stable. undergoes a reversible reaction that produces polyacrylamide, secondary amines, and formaldehyde. Furthermore, the protonated aminomethylated polymers of the present invention have a lower tendency to exhibits high pH 1, high alkalinity, high % volatiles or high aerobic decomposition slurry. Excellent performance in industrial and municipal wastewater with severe contaminants exhibiting %.

The Mannich flocculants of the present invention are preferably substantially linear, from about 0.1 to about 1 By using a commercially available water-soluble polyacrylamide with an intrinsic viscosity in the range of 9. It can be manufactured as follows. Alternatively, polyacrylamide (or polymethacrylamide) acrylamide monomer or methacrylamide monomer - (if a homopolymer is desired) or acrylamide monomer and methacrylic The reaction mixture containing both amide monomers (if a copolymer is desired) is free-radically catalyzed. It can be produced by forming it in the presence of a medium. Catalyst amount and type as well as producing polymers with different intrinsic viscosities by varying the reaction time. be able to. Forming polyacrylamide and polymethacrylamide polymers The method to do this is well known.

At least a portion of the amide groups on the polyacrylamide polymer are then exposed to form. Aminomethylated in a Mannich reaction using an aldehyde and a secondary amine.

A preferred secondary amine is dimethylamine, but diethylamine, methylethyl Amine, piperidine, di(β-hydroxyethyl)amine, hydroxyethyl Methylamine, diethylamine, pyrrolidone, diethanolamine and diallyl Other secondary amines may also be used, including amines. Forming such Mannich products The operation is described in US Pat. No. 3.328.901, British Patent Specification 1.572.386 No. and Schiller and Suen's U strike + 7 a. Le Engineer Chemistry, Volume 48, No. 12.2132-37 ( 1956).

As mentioned above, the available acrylamide groups in the polyacrylamide reactant are It may be desirable to aminomethylate less than all of the aminomethylated The amount of formaldehyde is determined by the amount of secondary amine in the Mannich reaction mixture or the amount of formaldehyde. It can be adjusted by adjusting either the amount. Generally, covered Conversion of 10-100% of the available amide groups depending on the discharge requirements of the treated water system This is desirable.

According to one aspect of the invention, the Mannich polymer is then added to the Mannich solution in the third phase. Rapidly adding an organic acid in substantially equal stoichiometric amounts to the aminoalkyl content This makes it acidic (protonated). Preferred organic acids are formic acid and vinegar. acid and propionic acid, although other water-soluble organic acids may also be used. The addition of organic acids is The pH of the flocculant solution is reduced from about 10.5 to about 6.5.

If it remains in this range, the flocculant rapidly degrades and crosslinks. acidic flocculant To ensure the stability of the system, the pH of the system is lower than about 4.5, preferably from about 3.0 to about Further reduction to the range of 3°5 is required. This can be achieved using mineral acids. Wear. Although the nature of the mineral acid is not critical, hydrochloric acid and sulfuric acid are particularly preferred.

Alternatively, Mannich polymers can be acidified using mineral acids alone to a p of less than 4.5. Concentrates with H can be formed. Such acidified polymers have good Although exhibiting flocculating properties, it is preferred to use mixed organic/mineral acid systems.

To avoid cross-linking and polymer degradation, the acid component and the Mannich polymer should be combined rapidly. It is important to mix quickly. A preferred method of acid addition is to add a mixture of organic and mineral acids to During the balanced flow of the Mannich polymer, the point is The injection is such that the pH of the remer is reduced substantially immediately below 4.5.

In preferred embodiments, the formula RM or RiM (wherein R is methyl, ethyl , propyl or butyl, M is sulfate, sulfite, chloride, From the group consisting of bromides, iosides, nitrates, nidrites and carbonates (selected) can be used in the acidified Mannich flocculant composition. sulfuric acid Dimethyl and methyl chloride are preferred water-soluble materials. Such compounds are present in small amounts. Improve the stability of the potato system. We believe that the compound is a tertiary amino acid in Mannich products. It was found that the system was improved when less than 0.1 equivalents were included based on the methyl group. I put it out. The optimum level of the compound is approximately 0.02 equivalents of tertiary aminomethyl group, That is, it is 2.0 mol% of the tertiary aminomethyl group.

Guest of the day The features of the invention will be explained in the following examples, with reference to the accompanying drawings in the case of Examples 4 to 6. It will be revealed.

Figure 1 shows the waste of four flocculant compositions used to treat wastewater from vapor mills. Indicates water performance. Curve A shows the present invention, in which the pH was adjusted by a mixture of mineral acids and acetic acid. Figure 3 shows a 30 mol% acidic Mannich polymer prepared according to the method. Curve B has a salt pH. 30 mole % acidic Mannich polymer prepared according to the invention, conditioned only with acid. - indicates. Curve C shows a sample of 30% produced according to the invention, the pH of which was adjusted only with sulfuric acid. Shows mole % acidic Mannich polymer. The curve is 90 mol% aminomethylated. Figure 1 shows a polyacrylamide (prior art composition). represented by curves A, B and C The curved composition had a polymer solids content of 3.2% and the curved composition had a polymer solids content of 4. ,0%.

FIG. 2 shows a Mannich flocculant prepared according to the present invention and a conventional Mannich flocculant. % aminomethylation when both were applied to samples taken from the same municipal wastewater source. The wastewater rates are compared for each of these polymers as a function. Curve E is a polymer Acid-stable molasses prepared according to the invention with some different degrees of aminomethylation The Mannich polymer is shown below. Curve F ranges from 10 to 100% aminomethyl represents a conventional, basic Mannich polymer with a polymerization.

Figure 3 shows i) two acidic agglomerate compositions prepared according to the invention (curves G and H); and ii) two conventional aminomethylated acrylamide polymers (curve I and J) are graphed as a function of polymer solids content.

E-yu Contains 2.219% polyacrylamide and has an intrinsic viscosity of 12 (rV12) 500 g of the aqueous solution was heated to 30°C (85°F). This heated polyacrylic Add 12.3g of dimethylamine aqueous solution (60%) and formaldehyde to the Ruamide solution. 12.6 g of an aqueous solution (37%) of H. Approximately 1 liter of the above Mannich reaction mixture pH 1 of 0.2-10.5 and temperature of about 32°C (90°F) held for 9 hours. Obtained The material is almost 100% aminomethylated and has a solids content of approximately 4%. Ta.

The above Mannich solution was divided into five 100mβ aliquots: Aliquot A is made by quickly adding 3.6 g of sulfuric acid and 4.5 g of water to 100 g of Mannich solution. Acidified with sulfuric acid by adding: Aliquot B is made by quickly adding 3.2 g of hydrochloric acid and 4.7 g of water to 100 g of Mannich solution. Acidified with hydrochloric acid by adding: Aliquot C consists of 100 g of Mannich solution, 0.98 g of acetic acid, 2.6 g of hydrochloric acid and Acidified with a mixture of hydrochloric acid and acetic acid by rapidly adding 4.7 g of water; Coat D consists of quickly adding 0.98 g of acetic acid, 2.9 g of sulfuric acid, and 4.7 g of water to 100 g of sample. acidified with sulfuric acid and acetic acid by rapid addition; and Aliquot E was prepared by adding 0.08 g (2 mol%) of dimethyl sulfate to the sample. was prepared in the same manner as aliquot D.

Five treated aliquots and a commercially available Mannich polymer sample (Diatic 4300 (Diatech Polymers, Batavia, Illinois) was stored at 40°C for 25 days. death.

Tested regularly for charge density and intrinsic viscosity. The test results are shown in Table 1. electric A decrease in loading density and an increase in viscosity indicate degradation (crosslinking) of the polymer.

The results showed that the stability of mixed organic/inorganic acid solutions compared to mineral acid-treated Mannichpolyte. limer and a conventional basic Mannich polymer control. ing. The results also showed that by adding a small amount (2%) of the compound dimethyl sulfate, This shows that the concentration solution was further stabilized.

Bottom-11 Stability study - over the following period Changes in viscosity and charge density g Poly7-); Viscosity is measured using a Brookfield viscometer (from spindle) This is the centipoise value measured at 5.12 rpm and 25°C.

Den--λ It has an intrinsic viscosity of 12. Habo 100% aminomethylated Mannich reaction product A series of protonated samples were formed in the same manner as aliquots A, B, C and D of Example 1. accomplished. These four samples and the commercially available nearly 100 mol% aminomethylated Mannich A control containing polymer (Diatic 4300) was compared with the NIOSH method, 125-1 It was sent to a private laboratory for formaldehyde content determination according to the regulations.

The results of the analysis are listed in Table 2. The data are based on samples treated with mixed organic/inorganic acids. was significantly lower in distilled formaldehyde than conventional Mannich polymers. It shows.

people-su Formaldehyde analysis customary mannich Control, ~100 mol% 3. OOppm Sulfuric Acid Sulfuric Acidification Top 10 0 mol% H 1.40 ppm Hydrochloric acid acidification ~100 mol% Mannich 0.97ppm Sulfuric acid, acetic acid acidification ~100 mol% Mannich o, e5ppm *All samples were nearly 100% aminomethylated, 2.7.1.0.0.7 and 0. A series of low molecular weight polyacrylamide polymers having an intrinsic viscosity of 4 was prepared using the procedure of Example 1. treatment with stoichiometric amounts of dimethylamine and formaldehyde according to ~100 % aminomethylated product was formed. For example, take a portion of each of the four low Mannich samples. Following the general procedure specified for aliquot D of 1, further treatment with acetic acid and sulfuric acid Acid denaturation with the basic counterpart of each low ■ substance, thereby forming acid Mannich products. The counterpart was obtained.

Each of the above samples and the polyethyleneimine (PEI) control was added to the cellulose fibers in water. Vine-like vapor stock used in the formation of boxboard, containing dispersed liquids and other additives. The drainage rate was tested by using The usage procedure is as follows : 1. Disperse an amount of flocculant polymer to fill 4 volumes of vapor stock in a large beaker. 2. Place the filter piece with one end connected to the vacuum source on the surface. Place it face down in the vapor stock and gently shake it up and down to prevent the flocculant from settling. Moved it. Continue this process for a total of 20 seconds; 3. After 20 seconds of vacuum filtration, remove the filter piece from the beaker and place it face up. It was placed on a ring stand and held under vacuum for 10 seconds. Then remove the vacuum; hand, 4. Measure the amount of water filtered and collected for 30 seconds.

Data from this experiment are recorded in Table 3. The data shows that each of the acid Mannich substances with substantially lower polymer loadings compared to its standard basic Mannich counterpart. , indicating that equal or higher drainage rates were achieved. The data also Compounding amount of relatively low molecular weight acid Mannich substance (■0.3) is 0.7j2b/ton The results were comparable to the polyethyleneimine control containing 1.01b/) of the compounded amount. It shows that the ■2.7 acid Mannich is only 0.2j2b/ton. volume even resulted in higher drainage rates. PEI in paperboard manufacturing is the lowest Because of the molecular weight, doses often have to be increased.

Table 3 shows that this constraint is achieved using acid Mannich polymers made according to the present invention. This example shows that there is no such thing. In addition, the molecular weight of the flocculant polymer may contribute to the drainage phenomenon. It is well understood that this plays a significant role in This effect is shown in Table 3. This can be understood by the fact that as the molecular weight of the polymer increases, the amount of polymer required decreases.

1-yu paperboard drainage Mannich (IV O, 4) 3.2 Mannich 122 acid (IV O, 3) 0.7 Mannitz 122 acid (IV O,7) 3.1 Mannits 122 acid (I V O, 7) 0.5 130 Mannitz (IV 1.0 > 3.0122 acid Mannitshi (IV 1.0) 0.4 128 Mannitshi (IV 2.71 3. 0 122 acid Mannich (IV 2.7) 0.2 134 all Mannich Flocculant is ~100% aminomethylated, rV = limiting viscosity.

Legend - One Hill A) Polyacrylic having an intrinsic viscosity of 12 (IV12) according to the general procedure of Example 1. for reacting an aqueous solution of acrylamide with 30% of the acrylamide groups on the polymer. Aminomethylation was carried out with sufficient dimethylamine and formaldehyde.

Three aliquots of the resulting 30 mol% Mannich material were divided into three aliquots: aliquot A from Example 1; With rapid protonation by acid in the same manner as B and D, i) sulfuric acid alone (i.e. Mannich polymer adjusted to pH 3 (without organic acid); ii) with hydrochloric acid (without organic acid); ii) a Mannich polymer adjusted to pH 3; and ii) a stoichiometry of the polymer. After the rapid addition of a suitable amount of acetic acid, the pH was adjusted to 3 by rapid addition of mineral acid, i.e. sulfuric acid. A bound acid ° Mannich polymer was formed. The resulting acid Mannich concentrate is approximately 3 ．． It had a solids content of 2%.

For the dilute solution of the above concentrate, dilute 15.6g of the concentrate with water to 100mj2. It was formed by with an intrinsic viscosity of 12 and a solids content of 4%, but about 90% Conventional basic Mannich concentrates with aminomethylated available acrylamide groups ( Diatic 4390) was used as a control. Control polymer solution prior to testing 12.5g was diluted with water to 100ml2.

Each of the above samples was added to the same municipal wastewater sample. Such wastewater often has a high electrical charge Flocculants with required amounts and requiring increased charge densities are conventionally required.

B) The performance of the sample flocculant material is determined by filtering the flocculant-treated sample at regular time intervals. , evaluated by measuring the volume of water passing through the filter. Test procedure According to the method, 10 mj2 of the dilute polymer solution prepared from Mannich concentrate was Add to 250 m of wastewater in a 00 m1 mixing cylinder and mix until homogeneous. It was stirred with Each treated sample was poured into a Buchner funnel and allowed to drain for 30 seconds.

The data obtained from the tests are summarized in Table 4.

FIG. 1 is an exemplary graph of the performance data listed in Table 4. All curves are active The drainage rate increases when the level of reactive polymer increases, even though the initial charge density is low. Regardless of the three 30% acid Mannich polymers (curves A to C), the 90% standard polymer This shows that the performance is superior to that of the Nich polymer (Curve D). data also showed that the organic/mineral acid combination (curve A) was more sensitive than any of the other systems tested. The coagulant required to achieve the same drainage rates as other Mannich flocculants shows substantially less collection agent and the highest absolute drainage rate. .

Bottom -4° Polymer active expressed as flocculant, nb per ton of wastewater solids; All flocculants had an intrinsic viscosity of 12.

**Diatic 4390, Diatec Polymers, Batavia, Illinois .

Polyacrylic with an intrinsic viscosity of 12 (IV12) was added to eight separate reaction flasks. An aqueous solution of amide was added.

10%, 20%, 30%, 40%, 50%, 70%, 9 Sufficient amount of diaminomethylated Mannich flocculant to form 0% and 100% aminomethylated Mannich flocculant. Methylamine and formaldehyde were added.

20%, 30% and 50% aminomethylated and 10% and 70% amino A portion of the methylated product was further processed according to the general procedure of Example 1, Aliquot D.

A portion of the Mannich polymer described above was used to treat municipal wastewater and Drainage rates were measured following the filtration procedure described in . The results of the processing are shown in Table 5, and This is shown graphically in Figure 2.

The data indicate that acidified, 30% aminomethylated manganese was used to treat this wastewater system. The Nich flocculant was superior to the conventional 90% aminomethylated standard Mannich. Illustrated. The data also show that using Mannich polymers with excess charge density As a result, acidified Mannich polymers and Illustrating the fact that the performance of flocculant compositions using standard Mannich polymers was reduced. There is.

table - once 90S 120 100S to.

*S = standard (non-acidified Mannich); A = Mannich acidification with acetic acid/sulfuric acid; of all polymers! ■ is 12 Ta.

milk-balls A) 12 ■ and about 40% aminomethylated according to Bart B's procedure in Example 4. A conventional basic Mannich flocculant with effective acrylamide groups was added to the wastewater solids content. Municipal waste in the Midwest using three different levels of polymer solids per ton. Treated the water. The results were as follows: B) the same Mannich polymer with stoichiometry equal to its tertiary aminomethyl content. acidify quickly with acetic acid, then add enough to adjust the pH to 3.0-3.5. Treated with sulfuric acid.

Following Bart B's procedure in Example 4, the same procedure was performed using four different levels of acidified polymer. We treated urban wastewater in the Midwest of the United States and obtained the following results: 4.60 100 5.20 110 5.80 127 C) Again following Bart B's procedure in Example 4, 12 IV and about 50% of the amino Using a conventional basic Mannich flocculant with methylated active acrylamide groups, The same municipal wastewater used in Bart A in this example was treated. The result is as below ( It was A 90 D) the same Mannich polymer with stoichiometry equal to its tertiary aminomethyl content. acidify quickly with a quantity of acetic acid, then add enough to adjust the pH to between 3.0 and 3.5. Treated with sulfuric acid.

Following Bart B's procedure in Example 4, the same procedure was performed using four different levels of acidified polymer. The same urban wastewater was treated and the following results were obtained: The results of these tests are shown in Figure 3; the data shows that the two acid Mannich polymers They show superior performance over their standard basic Mannich counterparts.

Drainage speed (st/30 seconds) international search report

Claims (1)

[Claims] (1) An aqueous and acidic flocculant concentrate comprising rapidly mixed components A) to C) below; A) (1) Polyacrylamide, polymethacrylamide and acrylamide a polymer selected from the group consisting of copolymers of tacrylamide; (2) a secondary amine; (3) Formaldehyde and A product containing a tertiary aminoalkyl group formed by the Mannich reaction of at least 1% by weight, B) a mineral acid in an amount sufficient to adjust the pH of the flocculant concentrate to less than about 4.5; C) water. (2) an aqueous and acidic flocculant concentrate comprising the following components A) to C); A) (1) Polyacrylamide, polymethacrylamide and acrylamide a polymer selected from the group consisting of copolymers of methacrylamide; (2) a secondary amine; (3) Formaldehyde and At least one of the products containing a tertiary aminoalkyl group formed by the Mannich reaction of 1% by weight, B) Substantially stoichiometric with the tertiary aminoalkyl group in the Mannich reaction product (1) (2) adjusting the pH of the flocculant concentrate to less than about 4.5; with a sufficient amount of mineral acid to wherein the acid component and the tertiary aminoalkyl group-containing product are C) Water that is rapidly mixed. (3) The flocculant concentrate according to claim 1 or 2, further comprising a compound of the following formula; RM or R2M (wherein R is methyl, ethyl, propyl or butyl, M is sulfate , sulfite, chloride, bromide, iodide, nitrate, nitrite and (selected from the group consisting of carbonates). (4) the above compound is less than 0.1 equivalent of the tertiary aminomethyl group in the Mannich product; The flocculant concentrate of claim 3 comprising: (5) The tertiary aminoalkyl group-containing product is from 2 to 20% by weight of the concentrate. A flocculant concentrate according to claim 1 or 2, comprising: (6) The concentrate of claim 2, wherein said organic acid comprises acetic acid. (7) The agglomerate according to claim 1 or 2, wherein the mineral acid is selected from the group consisting of sulfuric acid and hydrochloric acid. drug concentrate. (8) The amount of tertiary aminoalkyl groups in the concentrate is 3. A flocculant concentrate according to claim 1 or 2 consisting of 10% to 100% of mido groups. (9) The acrylamide group-containing polymer has an intrinsic viscosity of about 0.1 to about 19. A flocculant concentrate according to claim 1 or 2. (10) A method of forming an aqueous and acidic flocculant concentrate comprising the steps of: A) (1) Polyacrylamide, polymethacrylamide and acrylamide a polymer selected from the group consisting of copolymers of tacrylamide; (2) a secondary amine; (3) Formaldehyde and water containing at least 1% of a water-soluble Mannich polymer formed by the reaction of forming a solution; B) dissolving the tertiary aminoalkyl groups in the Mannich reaction product; rapidly adding a qualitatively stoichiometric equivalent of an organic acid to said aqueous solution; C) Raise the pH of the flocculant concentrate to about Adjusting the pH to less than 4.5. (11)a) Polyacrylamide, polymethacrylamide and acrylamide a polymer selected from the group consisting of copolymers with methacrylamide; b) a secondary amine; c) formaldehyde and Aqueous Mannich polymer agglomerates containing tertiary aminoalkyl groups prepared by the reaction of 1. A method of reducing reversibility of an agent, the method comprising: The pH of the above Mannich polymer flocculant can be adjusted by rapidly adding an acidic component. The method described above, comprising adjusting the temperature to be less than 4.5. (12)a) Polyacrylamide, polymethacrylamide and acrylamide a polymer selected from the group consisting of copolymers with methacrylamide; b) a secondary amine; c) formaldehyde and Aqueous Mannich polymer agglomerates containing tertiary aminoalkyl groups prepared by the reaction of 1. A method of increasing the reactivity of an agent, the method comprising: The pH of the above Mannich polymer flocculant can be adjusted by rapidly adding an acidic component. The method described above, comprising adjusting the temperature to be less than 4.5. (13) a) high pH material, b) material with high degree of alkylation, c) high proportion of volatiles and d) materials with a high proportion of aerobically decomposed sludge. aminomethylated to treat water containing at least one selected contaminant. A method using polyacrylamide, which uses the above Mannich polymer flocculant. adjusting the pH to less than 4.5 by rapidly adding an acid component. The above method. (14) The acid component is i) substantially stoichiometrically with the tertiary aminoalkyl group in the Mannich polymer; equivalent amount of organic acid and ii) the pH of the flocculant in combination with the organic acid is less than 4.5. with a sufficient amount of mineral acid to adjust the 14. The method of claim 11, 12 or 13, comprising: (15) The Mannich polymer comprises about 2% to about 20% of the aqueous solution. 15. The method according to any one of claims 10 to 14.